[PATCH 5/5] scalar diagnose: show a spinner while staging content

From: Johannes Schindelin via GitGitGadget <gitgitgadget@gmail.com>
Date: Jan 26, 2022, 08:41 UTC
Message-ID: <3a2cdce554a1755210592f3b9bb056d936ca98b6.1643186507.git.gitgitgadget@gmail.com>
In-Reply-To: <pull.1128.git.1643186507.gitgitgadget@gmail.com>

From: Johannes Schindelin <johannes.schindelin@gmx.de>

It can take a while to gather all the information that `scalar diagnose` wants to accumulate. Typically this happens when the user is in need of quick solutions and therefore their patience is tested already. By showing a little spinner that spins around, we hope to help the user muster just a tiny bit more patience until `scalar diagnose` is done.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
---
 contrib/scalar/scalar.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/contrib/scalar/scalar.c b/contrib/scalar/scalar.c
index c0ad4948215..224329f38f5 100644
--- a/contrib/scalar/scalar.c
+++ b/contrib/scalar/scalar.c
@@ -259,12 +259,26 @@ static int unregister_dir(void)
 	return res;
 }
 
+static void spinner(void)
+{
+	static const char whee[] = "|\010/\010-\010\\\010", *next = whee;
+
+	if (!next)
+		return;
+	if (write(2, next, 2) < 0)
+		next = NULL;
+	else
+		next = next[2] ? next + 2 : whee;
+}
+
 static int stage(const char *git_dir, struct strbuf *buf, const char *path)
 {
 	struct strbuf cacheinfo = STRBUF_INIT;
 	struct child_process cp = CHILD_PROCESS_INIT;
 	int res;
 
+	spinner();
+
 	strbuf_addstr(&cacheinfo, "100644,");
 
 	cp.git_cmd = 1;

-- 
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